Miriam Wennersten: Connecting Laser Ground Systems Across the Country
By Kendall Murphy
April 22, 2021
With only a few months left to prepare for the Laser Communications Relay Demonstration (LCRD) launch, Miriam Wennersten is applying the finishing touches to the mission’s country-wide ground segment.
“I’ve been part of LCRD since 2013, and I can’t wait for the system to start flowing data from Earth to space and back,” said Wennersten. “It has been a terrific experience and I have a fantastic team. I’m proud to have shared this experience with them.”
LCRD will showcase the benefits of optical communications, which offers missions higher data rates than comparable radio frequency systems, which most NASA missions use today. Optical communications uses infrared light to transmit data over long distances using lasers instead of radio waves, and results in systems that are faster, lighter, and more secure.
“Optical communications gives you higher bandwidth because it’s at a higher frequency, so you can pack more data per second. There are numerous science instruments in space collecting data, but we could not get it to the ground fast enough,” said Wennersten. “It’s like if you had a streaming library with unlimited movies and television shows, but you only had a dial-up modem, that wouldn’t do you any good. The same holds true to space, there is a limited amount of bandwidth and it comes down to how much power you can have on your spacecraft.”
As ground segment manager, Wennersten ensures LCRD’s ground stations, mission operations center, and radio frequency station are all ready to support the mission. She makes sure that each ground element is following the same script for interacting with the other elements and with the LCRD payload in orbit, and that they do so in a coordinated fashion.
The ground stations are located in Table Mountain, California and Haleakala, Hawaii, and were chosen for their altitude and weather patterns. Clear skies are ideal for laser communications because clouds can disrupt the communications. The mission operations center is located at NASA’s White Sands Complex in Las Cruces, New Mexico, where engineers will start LCRD’s activation process, turning on the payload and preparing it for data transmission. The Payload to the Ground Link Terminal is also located at the White Sands facility, and the electronics are right outside of the mission operations center. Before COVID-19, Wennersten would often travel to Las Cruces.
LCRD is the first mission where Wennersten is heavily involved in the ground side. Her area of expertise was flight hardware and software centric, but she has been with LCRD’s ground segment, helping wherever she can, for the past six years.
Before her involvement with NASA, Wennersten graduated from La Salle University in Philadelphia, Pennsylvania, with a bachelor’s degree in computer science. She started her career with NASA only eight weeks after receiving her bachelor’s degree and will celebrate her 32nd anniversary with the agency this June. She later continued her education journey at Johns Hopkins Whiting School of Engineering, earning her master’s degree in computer science.
When Wennersten started with the agency, she was hired for a flight software position with the Attitude Control and Stabilization Branch and had her first software fly in space only three years later. For the first Small Explorer: the Solar, Anomalous, Magnetospheric Particle Explorer, or SAMPEX mission, she wrote a program in the Intel 8085 assembly language to command and gather telemetry in the attitude control electronics box.
In the late 1990s, her branch head became interested in GPS for space, because space-qualified GPS receivers were not available for NASA satellites as navigation aids. Wennersten became the project development lead of a GPS receiver development team and saw the project through to its first demonstration in space. This was part of the relative navigation system experiments that flew on the last Hubble Space Telescope servicing mission, Shuttle Mission STS-125, in May 2009.
Once Wennersten transferred to the LCRD project, her first job was a data protocol engineer. She mapped data protocol transformations of commands and telemetry to confirm that the LCRD payload could read what was sent by the mission operations center and vice versa. Wennersten took on the role of LCRD’s flight software lead when the previous lead retired, and then moved into the ground segment manager position in 2017.
“Everything I’ve been involved in for the past 20 years has been in new technology and getting new technology to space. I want to continue supporting that and helping optical communications become commonplace,” Wennersten said. “I want to be a part of the optical communications revolution.”